---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-25-036483"
form_type: "8-K"
ticker: "ALMS"
cik: "0001847367"
company_name: "ALUMIS INC."
filed_at: "2025-04-21T23:59:59+00:00"
generated_at: "2026-05-23T10:36:02.332051+00:00"
event_type: "m_and_a"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Alumis and ACELYRIN amend merger terms; ACELYRIN stockholders get 48% ownership of combined company

## Summary
- Exchange ratio revised to 0.4814 Alumis shares per ACELYRIN share, up from original terms; Alumis stockholders own ~52%, ACELYRIN ~48% fully diluted.
- Special Meeting of Stockholders for both companies scheduled for May 13, 2025; record date April 1, 2025.
- Pro forma cash position of combined company ~$737M as of Dec 31, 2024; runway expected into 2027 for key data readouts.
- Stockholders representing ~62% of Alumis and ~24% of ACELYRIN have entered into voting agreements supporting the transaction.
- Merger expected to close in Q2 2025, subject to stockholder approvals and customary conditions.

## SEC filing metadata
- accession: 0001104659-25-036483
- form_type: 8-K
- ticker: ALMS
- cik: 0001847367
- company_name: ALUMIS INC.
- filed_at: 2025-04-21T23:59:59+00:00
- event_type: m_and_a
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 1.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1847367/000110465925036483/0001104659-25-036483-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1847367/000110465925036483/tm2512707d4_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-25-036483
- JSON: https://secwatch.observer/filing/0001104659-25-036483.json
- Plain text: https://secwatch.observer/filing/0001104659-25-036483.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.